Our goal is to test the hypothesis that short term bioassays have predictive powers for the risk of pneumoconiosis in man. This type of testing is important for evaluating exposures to new and complex dusts where pneumoconiosis risk is not known. While epidemiology is the primary method for assessing these risks, it is slow, expensive, requires large populations and may therefore not be feasible for new processes and materials. The project has three parts: l) Two air sampling techniques, high volume filtration and electrostatic precipitation, both with cyclone precollectors, will be evaluated for collecting bulk samples of respirable dust for bioassays; 2) A set of bioassays will be calibrated with a group of six pure or standardized materials that represent the full range of pneumoconiosis risks: iron oxide (lowest risk), talc, alpha-quartz, cristobalite (highest risk), and two NIOSH standardized coal dusts from Utah and Pennsylvania (intermediate risk). Samples of respirable particles will be given to hamsters by intratracheal instillation, and pulmonary lavage will be performed to determine: inflammatory response, proteolytic activity, fibrogenesis stimulation, cell damage, alteration in macrophage phagocytic activity and edema; 3) Respirable dust samples representative of worker exposures to complex dusts in Vermont talc and granite operations (stable for the past 15 years) will be collected and assayed to determine if the pattern of biological responses correlates with the risk of pneumoconiosis found by recent epidemiological studies. Personal samples will be collected on workers to verify that the composition and particle size distribution of the collected bulk dust is representative of worker exposures. The purpose of the three parts is to calibrate a test system and correlate it with human risk, rather than to develop an exact model of occupational lung disease. Our preliminary research has already demonstrated the feasibility of collecting and assaying occupational dusts.